Introduction: Medical errors have significant economic and clinical consequences and are considered as great challenges for the healthcare systems of different countries. With regard to the importance of medical errors, this study aimed to evaluate the frequency and type of medical errors in infected patients, admitted to the emergency department of Imam Reza (AS) Hospital in Kermanshah, Iran in 2014-2015.

Materials and Methods: In this cross-sectional, descriptive study, we evaluated medical errors affecting infected patients, admitted to the emergency department of Imam Reza (AS) Hospital in Kermanshah, Iran. Data were collected, using a questionnaire including demographic and clinical information and type of medical errors.

Results: Data were collected from 385 clinical records available at the emergency department of the hospital. In a total of 809 distinguished errors, the highest rates of error were as follows: medication errors (30%), CI 95%: 0.26-0.34), diagnostic errors (24.60%, CI 95%: 0.22-0.28), and admission for more than 6 h in the emergency room (14.34%, CI 95%: 0.12-0.16). Based on the findings, unnecessary prescription of antibiotics accounted for the highest percentage of medication errors (16.07%, CI 95%: 13.52-18.62).

Conclusion: According to the results of the present study, errors in diagnosis and treatment were the most frequent medical errors. Therefore, it is necessary to plan on reducing the frequency of these errors.